Transparent shader render issue/glitch

Hey there community,

recently I've been battling with the standard shader, since it seemed to have trouble rendering in Transparent and/or Fade-Mode.

I am generally new to shader scripting but managed to fix some sorting issues by enabling ZWrite and adding a depth only pass (source) to a copy of the standard shader - which also makes transparent meshes look nicer I guess.

No one issue remains, and it looks like this: (see image)

Note how the snout/face and other parts of the horse totally glitch out? The glitching changes based on viewpoint. Why is that and how can I fix it?

Any help is appreciated. Thx in advance!

PS: Im developing for iOS and Android, should I rather ditch the depth only pass since it costs more performance?